MySQL Set AutoReconnect

How to I set ‘autoReconnect=true’ in my KNIME DB Connector?

I recently set up a new machine with KNIME 4.1.1 and MySQL 8.0.19, then upgraded an old workflow with new DB Connectors and DB Writers. If I leave my workflow for 12 hours overnight then I run into the following error:

ERROR DB Writer 0:191:2825 Execute failed: The last packet successfully received from the server was 47,112,375 milliseconds ago. The last packet sent successfully to the server was 47,112,376 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.

I’m now trying to follow the recommendation to set the Connector/J connection property ‘autoReconnect=true’, but how? There seems to be three possible places in the DB Connector to set this. See the attached screenshots:

I found an old KNIME post from 2014 describing a similar problem and concluding that this setting was no help - that the problem could only be fixed on the MySQL server side:

Is that still true?

Hi @Edlueze,
yes it looks like you have to change the wait_timeout setting on the server site.
Also MySQL does not recommend the usage of autoReconnect.

best regards Mareike

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